This cake is lightly adapted from my paternal grandmother’s (G.G.’s) banana cake recipe. Well, I think of it as my grandmother’s recipe, but it was actually her mother’s or her mother-in-law’s ... either way, it lasted through the generations for a reason. It was a special cake that she would make for my father’s birthday, as it’s his favorite cake (and mine, too). The major difference between this cake and hers? Mine is made with banana peels (yes, really) instead of bananas. It’s a simple-seeming cake (no vanilla?! not a spice to be found?!), but it tastes just like your favorite banana bread.
Makes one 2-layer cake
- Peels from 2 very ripe bananas, stem and very bottom discarded (about 100 grams)
- 1/2 cup unsalted butter, softened, plus more for buttering the pans
- 1 1/2 cups granulated sugar
- 2 large eggs, separated
- 1/2 cup buttermilk
- 1 2/3 cups cake flour (210 grams), plus more flour (any type) for flouring the pans
- 1 teaspoon baking soda
- 1/4 teaspoon baking powder
- 1/2 teaspoon fine sea salt
- 1/2 cup butter
- 1 cup packed brown sugar
- 1/4 cup milk, 2 percent or higher
- 1 3/4 to 2 cups powdered sugar, sifted
To make the cake: Cut the banana peels into 1-inch pieces and place them in a small saucepan with 1 cup of water. Bring to a boil over medium-high heat, then reduce heat and simmer for 10 minutes. Remove the pan from the heat and allow the mixture to cool slightly, then strain the banana peels, reserving 1/4 cup of the cooking water.
Meanwhile, butter and flour the sides of two 8-inch round cake pans and line the bottoms with parchment paper. Butter and flour the pans again to coat the paper.
Transfer the peels and the 1/4 cup of cooking water to a tall, narrow container and puree until completely smooth with an immersion blender (a mini food processor would do the trick, too!).
Cream together the butter and sugar using an electric mixer (or a wooden spoon for an arm workout) until pale and fluffy, about 3 to 5 minutes. Add the egg yolks one at a time, mixing until incorporated, and scraping down the sides of the bowl after each addition. Mix in the banana peel mixture, then stir in the buttermilk until well combined.
In a separate medium-size bowl, whisk together the flour, baking soda, baking powder, and salt. Add the dry ingredients to the bowl with the butter mixture and stir gently, just until combined.
Put the egg whites in another bowl (make sure it’s clean and dry!) and whisk until soft peaks form—either by hand or with the whisk attachment on an electric mixer. If using an electric mixer, start slowly and gradually increase speed to medium-high. You’ll know you’re done when you pull out the whisk or beater and a soft peak is formed, but immediately collapses. Gently fold the egg whites into the batter and divide the batter evenly between the two prepared pans.
Bake for about 25 minutes, rotating the pans halfway through, until the top is golden and a toothpick inserted into the center of the cake pulls out with dry crumbs rather than wet batter. Let the cakes cool completely in the pans.
When the cakes are completely cool and you’re ready to assemble it, make the frosting. Melt the butter in a medium pan over low heat. Stir in the brown sugar and cook, stirring constantly, for 2 minutes. Stir in the milk, raise the heat to medium-high, and cook, stirring constantly until the mixture boils. Remove from the heat, and let cool until lukewarm. Gradually whisk in 1 3/4 cups powdered sugar, beating until smooth. Add the additional 1/4 cup powdered sugar if the frosting is too loose. Use the frosting immediately, as it will begin to thicken and stiffen as it sits.
When the cakes are completely cool, remove from the pans and peel off the parchment. Put one layer of the cake on a serving platter and spread about one third of the frosting evenly over the top. Set the other layer on top, and spread the remaining frosting over the top and sides of the cake.